Updated Iberian archeomagnetic catalogue: new full vector Paleosecular variation curve for the last three millennia

Abstract

Plain language summary In this work, we present 16 directional and 27 intensity high-quality values from Iberia. Moreover, we have updated the Iberian archeomagnetic catalogue published more than 10years ago with a considerable increase in the database. This has led to a notable improvement of both temporal and spatial data distribution. A full vector paleosecular variation curve from 1000 BC to 1900 AD has been developed using high-quality data within a radius of 900km from Madrid. A hierarchical bootstrap method has been followed for the computation of the curves. The most remarkable feature of the new curves is a notable intensity maximum of about 80T around 600 BC, which has not been previously reported for the Iberian Peninsula. We have also analyzed the evolution of the paleofield in Europe for the last three thousand years and conclude that the high maximum intensity values observed around 600 BC in the Iberian Peninsula could respond to the same feature as the Levantine Iron Age Anomaly, after travelling westward through Europe. Knowledge of the Earth's magnetic field plays an important role on the understanding of its dynamics. By measuring certain rocks or archeological objects from around the world, we can determine the field's shape and intensity in former times. Knowing its evolution is essential to understand how this field is generated, how it has varied through time and how it may behave in the future. In this work, we present new measurements of the magnetic field from the Iberian Peninsula that provide useful constraints on the magnetic field for archeological times that currently lack information. We have updated the compilation of Iberian data for the last 3,000years and calculated a new reference curve for the magnetic field for this region. We have found that the magnetic field was particularly intense in the Iberian Peninsula about 2,600 years ago. By comparing this result with data from Europe and the Middle East, we observe that this high intensity has been moving from east to west through southern Europe. This feature is probably related with the rapid intensity change (the geomagnetic spike) recently discovered in the Levantine region.